Getting to CampThis route is much less crowded than Avalanche Gulch, and very similar in profile. It may be about 1/4 to 1/2 mile longer than AG the way we did it. My group of 3 just did this hike last week in 2 days. Tried to camp at Hidden Valley but because we basically headed due north out of Horse Camp, we ended up on a ridge-top about 150 ft above Hidden Valley. We had a great view of the valley, the West Face Gully itself, and the Cascade Gulch route. However, to get to Hidden Valley from the ridge-top you have to descend down a steep slope that is about equal in steepness (or maybe a bit steeper) than any section of the actual West Face Gully. It can be done, since we did it on summit day to get into the valley and over to the WFG route, but with full packs on, we decided to just camp on a flat area on the ridge-top. There were a couple of areas of exposed rocks on the ridge so we were able to set up the tent on dirt instead of snow. Getting to this spot from Horse Camp required crossing over 3 minor ridgelines, the last 2 had exposed rocks/dirt/bushes.
If you want to get into Hidden Valley to camp I'd suggest you traverse northwest as you leave Horse Camp and follow the elevation contour lines across a few valleys until you're in the lower part of Cascade Gulch (maybe around 8300-8500ft). Then just go up the Gulch to Hidden Valley. You might be able to avoid crossing exposed rocks/dirt by doing this, but I'm not sure. We saw about 6 camps set up in the valley, all on exposed rock/dirt.
It took 9 hrs to get to camp but if I wasn't going with 2 beginners I could have probably done it in 4 hrs. And I'm an average-paced hiker, maybe a little slower than average when I'm carrying a 70 lb pack (17 lbs of that was my snowboard & boots).
Getting to SummitTwo of us left camp at 4:45am (3rd one had major blister issues). Took a long time getting down to Hidden Valley (we ended up side-stepping down the ridge to Hidden Valley). Then up the fairly wide chute that is at the bottom of the WF Gully proper. The Gully steadily gets steeper the higher you go until you get to the saddle at the ridgeline around 13,200ft. Once the sun hit the gully (forgot what time that was, maybe around 8:30am?) it got considerably hotter with only slight breezes once in a while. Due to the slower pace of my beginner partner (who eventually turned around at 12,100ft) I didn't get to the saddle until 1:30pm. If you have to choose, I'd head to the left as you're approaching the saddle. Gaining the saddle at the ridgeline seems easiest on the left. Then turn right on top (you'll see Misery Hill and the summit from the saddle) and traverse across the top of the Whitney Glacier. Maybe you're not actually on the glacier, it seemed more like a normal snow slope instead of a glacier. Either way, traverse over without gaining or losing much elevation. You'll eventually have to lose a bit of elevation as you traverse down and over to the south side of Misery Hill where you join the AG route and follow that to the summit. Alternately you can head up the west side of Misery hill, which no one was doing when I was there. You lose a little elevation getting to Misery Hill from the saddle no matter side of the Hill you want to hike up. Got to the summit at 3:05pm. Not feeling great, but OK. This was the 1st time hiking this route. I've done Avalanche Gulch 5 times (summitted 4 times) and Green Butte Ridge twice (summitted once). Although it took me almost 11 hrs this time, I'd estimate I could have done it in about 7 hrs, maybe 8 if I was solo. (I did Green Butte Ridge last year in about 6-7 hrs from the saddle camp near Old Ski Bowl @ 9k ft).
Getting downOnly took about 1 hr 45 mintues to get back to camp, and that included a good 30-45 minutes of sqeezing out my socks, putting crampons back on, and climbing back up the ridge above Hidden Valley to my camp. The glissading was awesome down the Gully. Started from about 100 ft below the saddle where it's practically a straight drop 3800 ft down to Hidden Valley. Getting back to the trailhead was an adventure, but it shouldn't be since it's easy to follow the same route back that you took to get up to camp.
The West Face Gully is also very popular for skiers/boarders to camp a couple of days in Hidden Valley and day hike the gully to ski/ride down. About 75% of the people on this route when we were there were carrying skis.
I'll try to post some pics in the general route description section, if I can't figure out how to post them in this trip report.